As ive been reading through all of the strats and noticed that people actually give specific numbers for how many of a certain unit to build. This is quite often a bad thing the more you progress into the game. First thing you need to do is ALWAYS have plenty of workers. Of course there is no specific number thats right or wrong. Experiment with the number of units you produce and never underestimate ANY unit.
One unit thats always underestimated is the Terran Vulture. What i like to do when im fighting people i know will use ground is make 10 vultures while making a good bit of units thats attack both air and ground for defence as i set up the 30 land mines the vultures have. After im done placing the land mines i send the vultures to attack my enemy, yes they are going on a suicide mission therfore theres no need in waiting to upgrade them. After they all die you will have 30 land mines and the 10 vultures you made, since they died you have used up no supply. GG ground.